package main

import (
	_ "embed"
	"fmt"
	"html"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"strings"
	"time"

	"github.com/spf13/cobra"
	"gopkg.in/yaml.v3"
)

// Embedded assets
//
//go:embed ../../licenses/MIT.txt
var mitLicense string

//go:embed ../../licenses/GPL-3.0.txt
var gplLicense string

//go:embed ../../licenses/AGPL-3.0.txt
var agplLicense string

//go:embed ../../licenses/Unlicense.txt
var unlicense string

//go:embed ../../.gitignore
var defaultGitignore string

type LicenseType string

const (
	LicenseMIT      LicenseType = "MIT"
	LicenseGPLv3    LicenseType = "GPLv3"
	LicenseAGPLv3   LicenseType = "AGPLv3"
	LicenseUnlicense LicenseType = "Unlicense"
)

type DeployType string

const (
	DeployDocker DeployType = "docker"
	DeployPyPI   DeployType = "pypi"
	DeployCargo  DeployType = "cargo"
	DeployGo     DeployType = "go"
)

type Config struct {
	Owner           string `yaml:"owner"`
	Name            string `yaml:"name"`
	License         string `yaml:"license"`
	DevelopBranch   string `yaml:"develop_branch"`
	DefaultGitignore bool   `yaml:"default_gitignore"`
	DefaultGitURL   string `yaml:"default_git_url"`
}

func defaultConfig() *Config {
	return &Config{
		Owner:           "",
		Name:            "",
		License:         "MIT",
		DevelopBranch:   "dev",
		DefaultGitignore: true,
		DefaultGitURL:   "https://git.theprivateserver.de/{owner}/{repo}.git",
	}
}

func getConfigPath() string {
	var home string
	if runtime.GOOS == "windows" {
		home = os.Getenv("USERPROFILE")
	} else {
		home = os.Getenv("HOME")
	}
	return filepath.Join(home, ".config", "GMS", ".config.yaml")
}

func loadConfig() (*Config, error) {
	configPath := getConfigPath()
	
	data, err := os.ReadFile(configPath)
	if err != nil {
		// Create default config
		config := defaultConfig()
		
		// Create config directory
		dir := filepath.Dir(configPath)
		if err := os.MkdirAll(dir, 0755); err != nil {
			return nil, err
		}
		
		// Write default config
		yamlData, err := yaml.Marshal(config)
		if err != nil {
			return nil, err
		}
		
		if err := os.WriteFile(configPath, yamlData, 0644); err != nil {
			return nil, err
		}
		
		fmt.Printf("Created default config at: %s\n", configPath)
		return config, nil
	}
	
	config := &Config{}
	if err := yaml.Unmarshal(data, config); err != nil {
		return nil, err
	}
	
	return config, nil
}

func runGitCommand(args []string, check bool) (string, error) {
	cmd := exec.Command("git", args...)
	output, err := cmd.CombinedOutput()
	
	if err != nil && check {
		return "", fmt.Errorf("git command failed: %v", err)
	}
	
	return strings.TrimSpace(string(output)), nil
}

func isGitRepo() bool {
	_, err := runGitCommand([]string{"rev-parse", "--git-dir"}, false)
	return err == nil
}

func getGitUserName() string {
	name, _ := runGitCommand([]string{"config", "user.name"}, false)
	return name
}

func decodeHTMLEntities(text string) string {
	return html.UnescapeString(text)
}

func getLicenseContent(licenseType LicenseType, owner string) string {
	var licenseText string
	
	switch licenseType {
	case LicenseMIT:
		licenseText = mitLicense
	case LicenseGPLv3:
		licenseText = gplLicense
	case LicenseAGPLv3:
		licenseText = agplLicense
	case LicenseUnlicense:
		licenseText = unlicense
	default:
		licenseText = mitLicense
	}
	
	licenseText = decodeHTMLEntities(licenseText)
	
	// Get fullname from git config or use owner
	fullname := getGitUserName()
	if fullname == "" {
		fullname = owner
	}
	
	currentYear := fmt.Sprintf("%d", time.Now().Year())
	
	// Substitute placeholders
	licenseText = strings.ReplaceAll(licenseText, "{year}", currentYear)
	licenseText = strings.ReplaceAll(licenseText, "{fullname}", fullname)
	
	return licenseText
}

func removeAllRemotes() {
	remotes, err := runGitCommand([]string{"remote"}, false)
	if err != nil {
		return
	}
	
	for _, remote := range strings.Split(remotes, "\n") {
		remote = strings.TrimSpace(remote)
		if remote != "" {
			runGitCommand([]string{"remote", "remove", remote}, false)
		}
	}
}

func setupGitRepo(config *Config, forceLicense bool) error {
	// Initialize repo if needed
	if !isGitRepo() {
		if _, err := runGitCommand([]string{"init"}, true); err != nil {
			return err
		}
		fmt.Println("Initialized new git repository")
	}
	
	// Ensure main branch exists
	branches, _ := runGitCommand([]string{"branch", "--list"}, false)
	if !strings.Contains(branches, "main") {
		if strings.TrimSpace(branches) == "" {
			runGitCommand([]string{"checkout", "-b", "main"}, true)
		} else {
			runGitCommand([]string{"branch", "-M", "main"}, true)
		}
	} else {
		runGitCommand([]string{"checkout", "main"}, false)
	}
	
	// Set up remote
	remoteURL := strings.ReplaceAll(config.DefaultGitURL, "{owner}", config.Owner)
	remoteURL = strings.ReplaceAll(remoteURL, "{repo}", config.Name)
	
	// Remove all existing remotes and add new origin
	removeAllRemotes()
	if _, err := runGitCommand([]string{"remote", "add", "origin", remoteURL}, true); err != nil {
		return err
	}
	fmt.Printf("Set remote 'origin' to: %s\n", remoteURL)
	
	// Add LICENSE if missing or forced
	licensePath := "LICENSE"
	if _, err := os.Stat(licensePath); os.IsNotExist(err) || forceLicense {
		var licenseType LicenseType
		switch config.License {
		case "GPLv3":
			licenseType = LicenseGPLv3
		case "AGPLv3":
			licenseType = LicenseAGPLv3
		case "Unlicense":
			licenseType = LicenseUnlicense
		default:
			licenseType = LicenseMIT
		}
		
		licenseContent := getLicenseContent(licenseType, config.Owner)
		if err := os.WriteFile(licensePath, []byte(licenseContent), 0644); err != nil {
			return err
		}
		fmt.Printf("Added LICENSE: %s\n", config.License)
	}
	
	// Add/overwrite .gitignore if enabled
	if config.DefaultGitignore {
		if err := os.WriteFile(".gitignore", []byte(defaultGitignore), 0644); err != nil {
			return err
		}
		fmt.Println("Added/updated .gitignore")
	}
	
	// Stage changes
	runGitCommand([]string{"add", "."}, true)
	
	// Commit if there are staged changes
	status, _ := runGitCommand([]string{"status", "--porcelain"}, false)
	if status != "" {
		if _, err := runGitCommand([]string{"commit", "-m", "Initial commit"}, true); err != nil {
			return err
		}
		fmt.Println("Created initial commit")
	}
	
	// Create and checkout dev branch
	devBranch := config.DevelopBranch
	runGitCommand([]string{"checkout", "-b", devBranch}, false)
	fmt.Printf("Created and switched to branch: %s\n", devBranch)
	
	// Try to push to remote
	_, err1 := runGitCommand([]string{"push", "-u", "origin", "main"}, false)
	_, err2 := runGitCommand([]string{"push", "-u", "origin", devBranch}, false)
	
	if err1 == nil && err2 == nil {
		fmt.Println("Pushed to remote successfully")
	} else {
		fmt.Println("⚠️  Warning: Could not push to remote. Network may be unavailable or remote not accessible.")
		fmt.Println("   Repository configured locally. Push manually when ready.")
	}
	
	return nil
}

func setupGiteaWorkflows(deployType DeployType) {
	giteaDir := ".gitea"
	workflowsDir := filepath.Join(giteaDir, "workflows")
	
	// Create directories
	os.MkdirAll(workflowsDir, 0755)
	
	// TODO: Copy/create workflow files based on deployType
	
	fmt.Printf("Set up Gitea workflows for: %s\n", deployType)
	fmt.Println("⚠️  Note: Ensure required secrets are configured in Gitea user/org settings:")
	fmt.Println("   - GITEA_TOKEN, TOKEN, REGISTRY, DOCKER_USERNAME")
	
	if deployType == DeployDocker {
		fmt.Println("⚠️  Warning: Docker workflows require a Dockerfile in the repository root.")
	}
}

var (
	owner            string
	name             string
	license          string
	developBranch    string
	defaultGitignore *bool
	defaultGitURL    string
	force            bool
	deployType       string
)

var rootCmd = &cobra.Command{
	Use:   "gitreposetup",
	Short: "Initialize and configure git repositories with licenses and workflows",
	Run: func(cmd *cobra.Command, args []string) {
		// Load config
		config, err := loadConfig()
		if err != nil {
			fmt.Fprintf(os.Stderr, "Error loading config: %v\n", err)
			os.Exit(1)
		}
		
		// Override config with CLI arguments
		if owner != "" {
			config.Owner = owner
		}
		if name != "" {
			config.Name = name
		}
		if license != "" {
			config.License = license
		}
		if developBranch != "" {
			config.DevelopBranch = developBranch
		}
		if defaultGitignore != nil {
			config.DefaultGitignore = *defaultGitignore
		}
		if defaultGitURL != "" {
			config.DefaultGitURL = defaultGitURL
		}
		
		// Validate required fields
		if config.Owner == "" || config.Name == "" {
			fmt.Fprintln(os.Stderr, "Error: --owner and --name are required (or set in config file)")
			os.Exit(1)
		}
		
		// Setup git repository
		if err := setupGitRepo(config, force); err != nil {
			fmt.Fprintf(os.Stderr, "Error setting up git repository: %v\n", err)
			os.Exit(1)
		}
		
		// Setup workflows if requested
		if deployType != "" {
			setupGiteaWorkflows(DeployType(deployType))
		}
		
		fmt.Println("\n✅ Repository setup complete!")
	},
}

func init() {
	rootCmd.Flags().StringVar(&owner, "owner", "", "Repository owner/organization name")
	rootCmd.Flags().StringVar(&name, "name", "", "Repository name")
	rootCmd.Flags().StringVar(&license, "license", "", "License type (MIT, GPLv3, AGPLv3, Unlicense)")
	rootCmd.Flags().StringVar(&developBranch, "develop-branch-name", "", "Development branch name (default: dev)")
	defaultGitignore = rootCmd.Flags().Bool("default-gitignore", true, "Use default .gitignore")
	rootCmd.Flags().StringVar(&defaultGitURL, "default-git-url", "", "Git remote URL template")
	rootCmd.Flags().BoolVar(&force, "force", false, "Force overwrite existing LICENSE")
	rootCmd.Flags().StringVar(&deployType, "deploy-type", "", "Deployment type for Gitea workflows (docker, pypi, cargo, go)")
}

func main() {
	if err := rootCmd.Execute(); err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
}